In general, a device is limited to certain functions that its original hardwares provide. This restricts the usefulness, flexibility and customize-ability of the device. Some mobile devices may encompass a mechanical coupling device, which is laid out for positive-fit coupling of a rear-side.
For example, patent application with publication no. DE 195 20 947 A1 describes in a general manner a personal computer, which displays the design of a flip-open laptop with alphanumeric keyboard and monitor and which is designed as a telecommunication device combining the functions of a telephone, radio or data transmission device. In addition, it has an interface for memory cards. Monitor and keyboard of the computer are connected with a pivot function on its longitudinal side and overlap each other in the closed position.
For example, a power supply designed in the same size as the general device is disposed flush with the rear side of the computer section.
As such the lack of individual adaptability (customize-ability) of the mobile device to individual requirements of the user presents a disadvantage. The user is forced to select expansion components and connect them via an external interface, according e.g. to the so-called USB-standard, to the mobile device by means of mechanical, electrical and signal technology. Subsequently, the user must load software suitable for the expansion component into the processor of the mobile device via e.g. a software drive of the mobile device. But a disadvantage still remains in that the installation is troublesome and the user has to handle two mechanically distinct devices.
Personal computers can be customized to the personal requirements of the user through expansion cards and thus be upgraded to serve additional functions, whereby the expansion cards are solidly and removably connected to the computer and they are slotted, bolted or inserted into the motherboard mostly in the interior of the device housing.
Mobile communication devices, e.g. so-called PDA's and smart phones can be placed on or in a holder and then docked to an interface of an expansion component using a cable connection or by wireless means. All the holders share the feature that they serve to hold the mobile device or the expansion component at a particular location determined by the user and that they enclose the mobile device or the expansion component. As an option, holders can also feature additional functions as the power supply for the mobile device or additional external interfaces.
One skilled in the art may understand that smart phones offer possibilities of customer-specific hardware adaptation, which can be divided into the following three categories: expansion via wireless interfaces, expansion via connections conducting electricity and passive elements as housings, replaceable housing covers and protective sleeves.
Wireless interfaces such as Bluetooth, WiFi, infrared and others do not transmit energy or power and hence a second battery or a second charging unit is required.
Connections conducting electricity, such as audio connection via headphone plug, USB, firewire or others, result in a large, external, clumsy and mechanically unstable attachment especially via cable, and thus there is a risk of breaking off a plug.
Smart phones feature a display screen and a hard or soft keyboard on the front side. The other surfaces are either hardly or not utilized at all and lie fallow. For example the rear side in numerous smart phones is hardly used, except having solely the camera lens and a flash light.
It is also widespread to place a mobile device in a protective sleeve. The purpose of protective sleeves is to protect mobile devices against mechanical, physical, chemical or electromagnetic damage and they encompass the mobile device wholly or at least partially.